Fuel - Check Valve ?

bgbird

Seaman Apprentice
Joined
Jun 13, 2004
Messages
44
I have a Sailfish 176 with a 60 gallon in-boat tank. Apparently I have an air leak somewhere. I can pump the primer bulb hard start the engine - but then the bulb goes soft. I also hear a sucking sound when I pump gas with the motor off.<br />The motor does run but seems to idle better when running from a 6.5 gallon outboard tank that I used for testing as opposed to the in-boat tank.<br /><br />One thing that makes me think that there is a leak is that I filled the outboard tank with the primer bulb connected to the separator. I submerged the recieving end of the hose in gas. When I squeezed the bulb I saw little air bubbles. I assumed that I would be able to create a siphon but I needed to squeeze the bulb constantly to fill the thank - and there were bubbles with each squeeze.<br /><br />The boat has a Suzuki DT100, connected to a primer bulb, then to a fuel/water separator - then to the tank. I tested everything from the separator out - and it seems to hold pressure. <br /><br />I'm thinking of replacing the last fuel line from the separator to the tank and removing the check valve there to take it out of the equation.<br /><br />Since the primer bulb has a built-in check valve, to I need to replace the one at the fuel tank?<br /><br />Exactly what purpose does this at the tank check valve serve and what are the ramifications of removing it?
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Fuel - Check Valve ?

Moving to Boats
 

Bayrider

Petty Officer 2nd Class
Joined
Apr 4, 2004
Messages
113
Re: Fuel - Check Valve ?

Hi bgbird. <br />When the fuel tank is full does the bulb still draw air, if not, take the check valve out and inspect the lift pipe for damage.Also check the valve for blockage by debris witch could be stopping the valve from opperating.The valve stops the fuel running back to the tank when the engine stops thus making it easier to prim next startup.
 

bgbird

Seaman Apprentice
Joined
Jun 13, 2004
Messages
44
Re: Fuel - Check Valve ?

Shouldn't the check valve in the primer bulb maintain siphon and not let gas go back to the tank?
 

Bayrider

Petty Officer 2nd Class
Joined
Apr 4, 2004
Messages
113
Re: Fuel - Check Valve ?

Hi bgbird. <br />In my experience with the primer bulb is that it will hold the siphon on the day of use.Next time out you have to prime again.Is that what you find,if so then that tells me the valve in the bulb isn,t as good as the one in the tank.BTW does the bulb draw air when the 60 gallon tank is full. <br /> Regards. :)
 
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